diff --git a/eloadas.html b/eloadas.html
new file mode 100644
index 0000000000000000000000000000000000000000..a254d27c440358ed4cb0810bccc463a644cc483c
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+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta name="generator" content="pandoc">
+  <meta name="author" content="TĂłth MiklĂłs">
+  <meta name="dcterms.date" content="2021-03-21">
+  <title>Linux elĹadĂĄs</title>
+  <meta name="apple-mobile-web-app-capable" content="yes">
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+<body>
+  <div class="reveal">
+    <div class="slides">
+
+<section id="title-slide">
+  <h1 class="title">Linux elĹadĂĄs</h1>
+  <p class="author">TĂłth MiklĂłs</p>
+  <p class="date">March 21, 2021</p>
+</section>
+
+<section id="pĂĄr-egyĂŠb-hasznos-parancs" class="slide level1">
+<h1>PĂĄr egyĂŠb hasznos parancs</h1>
+</section>
+<section id="wc" class="slide level1">
+<h1><code>wc</code></h1>
+<ul>
+<li>word counter</li>
+<li>szavak, sorok szĂĄmolĂĄsa</li>
+</ul>
+<pre class="shell-session"><code>[mike@thinkyboi ~]$ echo &quot;egy kĂŠt hĂĄ&quot; | wc -w
+3
+[mike@thinkyboi ~]$ echo &quot;egy kĂŠt hĂĄ&quot; | wc -l
+1
+[mike@thinkyboi ~]$ echo &quot;egy
+kĂŠt
+hĂĄ&quot; | wc -l
+3</code></pre>
+</section>
+<section id="tr" class="slide level1">
+<h1><code>tr</code></h1>
+<ul>
+<li>karaktereket cserĂŠl ki vagy tĂśrĂśl</li>
+</ul>
+<pre class="shell-session"><code>[mike@thinkyboi ~]$ echo &quot;almafa&quot; | tr &quot;a&quot; &quot;e&quot;
+elmefe
+[mike@thinkyboi ~]$ echo &quot;almafa kĂśrtefa eperfa&quot; | tr &quot; &quot; &quot;\n&quot;
+almafa
+kĂśrtefa
+eperfa
+[mike@thinkyboi ~]$ echo &quot;almafa&quot; | tr -d &quot;a&quot;
+lmf</code></pre>
+</section>
+<section id="curl" class="slide level1">
+<h1><code>curl</code></h1>
+<ul>
+<li>http shellbĹl</li>
+<li>stdout-ra Ărja ki, kivĂŠve, ha van <code>-o</code> kapcsolĂł</li>
+</ul>
+<pre class="shell-session"><code>[mike@thinkyboi ~]$ curl https://home.sch.bme.hu/~mikewashere/linux/eloadas.md | grep stdout
+  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
+                                 Dload  Upload   Total   Spent    Left  Speed
+100   777  100   777    0     0  33782      0 --:--:-- --:--:-- --:--:-- 33782
+- stdout-ra Ărja ki
+[mike@thinkyboi ~]$ curl https://home.sch.bme.hu/~mikewashere/linux/eloadas.md -o eloadas.md
+  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
+                                 Dload  Upload   Total   Spent    Left  Speed
+100   777  100   777    0     0  31080      0 --:--:-- --:--:-- --:--:-- 31080
+[mike@thinkyboi ~]$ </code></pre>
+</section>
+<section id="sh-fileok" class="slide level1">
+<h1><code>.sh</code> fileok</h1>
+<ul>
+<li>shell automatizĂĄlĂĄsa</li>
+<li>mintha soronkĂŠnt kiadnĂĄnk a parancsokat</li>
+</ul>
+</section>
+<section id="egy-.sh-file" class="slide level1">
+<h1>egy <code>.sh</code> file</h1>
+<pre class="shell-session"><code>[mike@thinkyboi tmp]$ vi test.sh
+[mike@thinkyboi tmp]$ cat test.sh 
+echo &quot;ez simĂĄn mĹąkĂśdik&quot; | cowsay
+curl &quot;https://home.sch.bme.hu/~mikewashere/linux/eloadas.md&quot; | grep &quot;soronkĂŠnt&quot; | cowsay
+
+[mike@thinkyboi tmp]$ bash test.sh 
+ _____________________ 
+&lt; ez simĂĄn mĹąkĂśdik &gt;
+ --------------------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||
+  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
+                                 Dload  Upload   Total   Spent    Left  Speed
+100  1596  100  1596    0     0  69391      0 --:--:-- --:--:-- --:--:-- 69391
+ _________________________________ 
+/ - mintha soronkĂŠnt kiadnĂĄnk a \
+\ parancsokat                     /
+ --------------------------------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||
+[mike@thinkyboi tmp]$ </code></pre>
+</section>
+<section id="shebang" class="slide level1">
+<h1>shebang</h1>
+<ul>
+<li>file futtatĂĄsakor a kernel meglesi mi van az elejĂŠn</li>
+<li>el tudunk indĂtani scripteket programkĂŠnt</li>
+<li><code>#!&lt;program&gt;</code></li>
+</ul>
+</section>
+<section id="shebang-1" class="slide level1">
+<h1>shebang</h1>
+<pre class="shell-session"><code>[mike@thinkyboi tmp]$ vi test.sh 
+[mike@thinkyboi tmp]$ cat test.sh 
+#!/bin/bash
+echo &quot;ez simĂĄn mĹąkĂśdik&quot; | cowsay
+curl &quot;https://home.sch.bme.hu/~mikewashere/linux/eloadas.md&quot; | grep &quot;soronkĂŠnt&quot; | cowsay
+
+[mike@thinkyboi tmp]$ chmod +x test.sh 
+[mike@thinkyboi tmp]$ ./test.sh 
+ _____________________ 
+&lt; ez simĂĄn mĹąkĂśdik &gt;
+ --------------------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||
+  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
+                                 Dload  Upload   Total   Spent    Left  Speed
+100  1596  100  1596    0     0  11319      0 --:--:-- --:--:-- --:--:-- 11319
+ _________________________________ 
+/ - mintha soronkĂŠnt kiadnĂĄnk a \
+\ parancsokat                     /
+ --------------------------------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||
+[mike@thinkyboi tmp]$ </code></pre>
+</section>
+<section id="tĹązfal" class="slide level1">
+<h1>tĹązfal</h1>
+<ul>
+<li>a kernel belsejĂŠben -&gt; gyors, de low-level</li>
+<li>iptables</li>
+<li>kĂŠnyelmesebb egy tĹązfal-kezelĹ</li>
+</ul>
+</section>
+<section id="ufw" class="slide level1">
+<h1>UFW</h1>
+<ul>
+<li>uncomplicated firewall</li>
+<li>egyszerĹą</li>
+</ul>
+<pre class="shell-session"><code>[mike@thinkyboi tmp]$ sudo ufw allow 80
+Rules updated
+Rules updated (v6)
+[mike@thinkyboi tmp]$ sudo ufw allow https
+Rules updated
+Rules updated (v6)
+[mike@thinkyboi tmp]$ sudo ufw enable</code></pre>
+</section>
+<section id="ssh-kulcsok" class="slide level1">
+<h1>SSH kulcsok</h1>
+<ul>
+<li>biztonsĂĄgosabb, mint egy jelszĂł</li>
+<li>sok algoritmus, RSA, elliptikus gĂśrbĂŠk</li>
+<li>publikus-privĂĄt</li>
+<li>privĂĄt sajĂĄt gĂŠpen, vĂŠdve</li>
+<li>publikus ott, ahova belĂŠpnĂŠnk</li>
+<li><code>~/.ssh/authorized_keys</code></li>
+</ul>
+</section>
+<section id="generĂĄlĂĄs" class="slide level1">
+<h1>GenerĂĄlĂĄs</h1>
+<pre class="shell-session"><code>mike@thinkyboi:~$ ssh-keygen
+Generating public/private rsa key pair.
+Enter file in which to save the key (/home/mike/.ssh/id_rsa): 
+Created directory &#39;/home/mike/.ssh&#39;.
+Enter passphrase (empty for no passphrase): 
+Enter same passphrase again: 
+Your identification has been saved in /home/mike/.ssh/id_rsa
+Your public key has been saved in /home/mike/.ssh/id_rsa.pub
+The key fingerprint is:
+SHA256:tYZX08XEZfJP5j/um2Y9KUgG+jffe82ONwgzkt4p0hc mike@thinkyboi
+The key&#39;s randomart image is:
++---[RSA 3072]----+
+|              .+*|
+|             . =o|
+|          . o . +|
+|         + o . +.|
+|        S *     o|
+|       . = E    .|
+|        + = B .o=|
+|       . = B ooBO|
+|        . + o.*XB|
++----[SHA256]-----+
+mike@thinkyboi:~$ cat .ssh/id_rsa.pub 
+ssh-rsa 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 mike@thinkyboi
+mike@thinkyboi:~$ </code></pre>
+</section>
+<section id="operĂĄtor" class="slide level1">
+<h1><code>&gt;&gt;</code> operĂĄtor</h1>
+<ul>
+<li><code>&gt;</code> tesĂłja</li>
+<li>filehoz appendĂĄl</li>
+</ul>
+<pre class="shell"><code>curl https://git.sch.bme.hu/mikewashere.keys &gt;&gt; ~/.ssh/authorized_keys</code></pre>
+</section>
+<section id="hĂĄzi-feladatok" class="slide level1">
+<h1>HĂĄzi Feladatok</h1>
+</section>
+<section id="alap-hĂĄzi" class="slide level1">
+<h1>Alap hĂĄzi</h1>
+<p>CsinĂĄlj felhasznĂĄlĂłt a csapattĂĄrsaidnak a VM-edre Ăşgy, hogy hozzĂĄfĂŠrjenek a statikus weboldalak mappĂĄjĂĄhoz, ezutĂĄn prĂłbĂĄljĂĄtok ki, hogy valĂłban hozzĂĄfĂŠrtek-e ĂŠs ha igen, rakjatok valami funky html-t a mappĂĄnba ajĂĄndĂŠkba a tĂĄrsaitoknak.</p>
+<p>Hint: adduser/useradd, usermod/gpasswd, chmod.</p>
+</section>
+<section id="side-quest" class="slide level1">
+<h1>Side Quest</h1>
+<p>ĂllĂts be kulcsos hitelesĂtĂŠst a kĂŠpzĂŠs VM-eden az SSH kapcsolatodhoz. Ehhez szĂźksĂŠged lesz egy privĂĄt ĂŠs egy publikus kulcsra a kliensgĂŠpeden.</p>
+<p>Hint: ssh-keygen.</p>
+</section>
+<section id="expert-sudo" class="slide level1">
+<h1>Expert (sudo)</h1>
+<p>Nyomozz hogyan ĂŠs miĂŠrt mĹąkĂźdik a sudo parancs! Ha megtalĂĄltad prĂłbĂĄld meg Ăśsszefoglalni nekĂźnk nĂŠhĂĄny mondatban.</p>
+<p>Hint: setuid</p>
+</section>
+<section id="expert-csomag-mĂĄgus" class="slide level1">
+<h1>Expert (Csomag mĂĄgus)</h1>
+<p>KĂŠszĂts egy Ăşj csomagot (package) egy ĂĄltalad vĂĄlaszott programbĂłl (sajĂĄt program is lehet), egy ĂĄltalad vĂĄlasztott disztribĂşciĂłhoz.</p>
+</section>
+<section id="jĂł-munkĂĄt" class="slide level1">
+<h1>JĂł munkĂĄt</h1>
+</section>
+    </div>
+  </div>
+
+  <script src="https://unpkg.com/reveal.js@^4//dist/reveal.js"></script>
+
+  // reveal.js plugins
+  <script src="https://unpkg.com/reveal.js@^4//plugin/notes/notes.js"></script>
+  <script src="https://unpkg.com/reveal.js@^4//plugin/search/search.js"></script>
+  <script src="https://unpkg.com/reveal.js@^4//plugin/zoom/zoom.js"></script>
+
+  <script>
+
+      // Full list of configuration options available at:
+      // https://revealjs.com/config/
+      Reveal.initialize({
+      
+        // Push each slide change to the browser history
+        history: true,
+
+        // reveal.js plugins
+        plugins: [
+          RevealNotes,
+          RevealSearch,
+          RevealZoom
+        ]
+      });
+    </script>
+    </body>
+</html>
diff --git a/eloadas.md b/eloadas.md
index 5305f49bd6e90aa268c5f152305aefe0e1593ec6..9cd2249e948403375526b549e1c783f0bca70e17 100644
--- a/eloadas.md
+++ b/eloadas.md
@@ -4,7 +4,7 @@
 
 # PĂĄr egyĂŠb hasznos parancs
 
-## `wc`
+# `wc`
 
 - word counter
 - szavak, sorok szĂĄmolĂĄsa
@@ -20,7 +20,7 @@ hĂĄ" | wc -l
 3
 ```
 
-## `tr`
+# `tr`
 
 - karaktereket cserĂŠl ki vagy tĂśrĂśl
 
@@ -35,7 +35,7 @@ eperfa
 lmf
 ```
 
-## `curl`
+# `curl`
 
 - http shellbĹl
 - stdout-ra Ărja ki, kivĂŠve, ha van `-o` kapcsolĂł
@@ -58,6 +58,8 @@ lmf
 - shell automatizĂĄlĂĄsa
 - mintha soronkĂŠnt kiadnĂĄnk a parancsokat
 
+# egy `.sh` file
+
 ```shell-session
 [mike@thinkyboi tmp]$ vi test.sh
 [mike@thinkyboi tmp]$ cat test.sh 
@@ -94,6 +96,8 @@ curl "https://home.sch.bme.hu/~mikewashere/linux/eloadas.md" | grep "soronkĂŠnt"
 - el tudunk indĂtani scripteket programkĂŠnt
 - `#!<program>`
 
+# shebang
+
 ```shell-session
 [mike@thinkyboi tmp]$ vi test.sh 
 [mike@thinkyboi tmp]$ cat test.sh 
@@ -132,7 +136,7 @@ curl "https://home.sch.bme.hu/~mikewashere/linux/eloadas.md" | grep "soronkĂŠnt"
 - iptables
 - kĂŠnyelmesebb egy tĹązfal-kezelĹ
 
-## UFW
+# UFW
 
 - uncomplicated firewall
 - egyszerĹą
@@ -156,10 +160,10 @@ Rules updated (v6)
 - publikus ott, ahova belĂŠpnĂŠnk
 - `~/.ssh/authorized_keys`
 
-## GenerĂĄlĂĄs
+# GenerĂĄlĂĄs
 
 ```shell-session
-mike@đĽ:~$ ssh-keygen
+mike@thinkyboi:~$ ssh-keygen
 Generating public/private rsa key pair.
 Enter file in which to save the key (/home/mike/.ssh/id_rsa): 
 Created directory '/home/mike/.ssh'.
@@ -168,7 +172,7 @@ Enter same passphrase again:
 Your identification has been saved in /home/mike/.ssh/id_rsa
 Your public key has been saved in /home/mike/.ssh/id_rsa.pub
 The key fingerprint is:
-SHA256:tYZX08XEZfJP5j/um2Y9KUgG+jffe82ONwgzkt4p0hc mike@đĽ
+SHA256:tYZX08XEZfJP5j/um2Y9KUgG+jffe82ONwgzkt4p0hc mike@thinkyboi
 The key's randomart image is:
 +---[RSA 3072]----+
 |              .+*|
@@ -181,9 +185,9 @@ The key's randomart image is:
 |       . = B ooBO|
 |        . + o.*XB|
 +----[SHA256]-----+
-mike@đĽ:~$ cat .ssh/id_rsa.pub 
-ssh-rsa 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 mike@đĽ
-mike@đĽ:~$ 
+mike@thinkyboi:~$ cat .ssh/id_rsa.pub 
+ssh-rsa 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 mike@thinkyboi
+mike@thinkyboi:~$ 
 ```
 
 # `>>` operĂĄtor
@@ -193,3 +197,35 @@ mike@đĽ:~$
 ```shell
 curl https://git.sch.bme.hu/mikewashere.keys >> ~/.ssh/authorized_keys
 ```
+
+# HĂĄzi Feladatok
+
+# Alap hĂĄzi
+
+CsinĂĄlj felhasznĂĄlĂłt a csapattĂĄrsaidnak a VM-edre Ăşgy, hogy
+hozzĂĄfĂŠrjenek a statikus weboldalak mappĂĄjĂĄhoz,
+ezutĂĄn prĂłbĂĄljĂĄtok ki, hogy valĂłban hozzĂĄfĂŠrtek-e
+ĂŠs ha igen, rakjatok valami funky html-t a mappĂĄnba ajĂĄndĂŠkba a tĂĄrsaitoknak.
+
+Hint: adduser/useradd, usermod/gpasswd, chmod.
+
+# Side Quest
+
+ĂllĂts be kulcsos hitelesĂtĂŠst a kĂŠpzĂŠs VM-eden az SSH kapcsolatodhoz.
+Ehhez szĂźksĂŠged lesz egy privĂĄt ĂŠs egy publikus kulcsra a kliensgĂŠpeden.
+
+Hint: ssh-keygen.
+
+# Expert (sudo)
+
+Nyomozz hogyan ĂŠs miĂŠrt mĹąkĂźdik a sudo parancs!
+Ha megtalĂĄltad prĂłbĂĄld meg Ăśsszefoglalni nekĂźnk nĂŠhĂĄny mondatban.
+
+Hint: setuid
+
+# Expert (Csomag mĂĄgus)
+
+KĂŠszĂts egy Ăşj csomagot (package) egy ĂĄltalad vĂĄlaszott programbĂłl
+(sajĂĄt program is lehet), egy ĂĄltalad vĂĄlasztott disztribĂşciĂłhoz.
+
+# JĂł munkĂĄt
diff --git a/hf.md b/hf.md
index 6191c26d9a3e54d3810220f51abd0a7c5b554753..a263cfc359acc9264ca9fa8488e681153187516e 100644
--- a/hf.md
+++ b/hf.md
@@ -26,4 +26,4 @@ Hint: setuid
 ## Expert (Csomag mĂĄgus) 
 
 KĂŠszĂts egy Ăşj csomagot (package) egy ĂĄltalad vĂĄlaszott programbĂłl 
-(sajĂĄt program is lehet), egy ĂĄltalad vĂĄlasztott disztribĂşciĂłhoz.
\ No newline at end of file
+(sajĂĄt program is lehet), egy ĂĄltalad vĂĄlasztott disztribĂşciĂłhoz.